Method and apparatus for treating plants



May 30, 1933' H. c. LASSEN ET AL ,912,209 METHOD AND APPARATUS FOR TREATING PLANTS Filed July 9, 1 930 Patented May 30, 1933 UNITED STATES PATIENT OFFICE HARRY LASSEN AND H ENRY DAHL, OF SAN JOSE, CALIFORNIA, ASSIGNORS TO FOOD MACHINERY CORPORATION, OF SAN JOSE, CALIFORNIA, A CORPORATION OF DELA:

WARE METHOD AND APPARATUS FOR TREATING PLANTS Application filed July 9,

This invention relates to the horticultural arts and altho it is capable of application to the cultivation and treatment of any kind of plants, it is especially useful in connection with the art of floriculture as practiced in greenhouses and the like.

The ravages of injurious pests, such as thrips, lice and fungus spores and the like, which attack and destroy plant life are the source of yearly losses of large proportions to florists and other greenhouse operators. In moderate weather the spreadof these pests can be checked and the damage done by them kept within reasonable bounds purpose.

by spraying the plants from time to time with suitable substances toxic to undesirable organisms such as nicotine solutions and the like which are very effective for this However, any increase in temperature serves to increase their activity and cause them to multiply more rapidly so that on hot days when the temperature in the greenhouses rises abnormally, immediate measures must be taken to destroy them or they cause a large amount of damage in the space of a few hours.

It is desirable to prevent the temperature from rising too high in the greenhouse, not only for protection against pests, but also because the heat causes unduly rapid evaporation of moisture from the plants with resultant-injury to them. Attempts have been made to lowerthe temperature and supply the plants with the necessary moisture by means of sprinkling but it has been found that the temperature cannot be sufliciently lowered in this manner and the moisture is evaporated from the surfaces of the plants faster than they can absorb it from the earth.

1930. Serial No. 466,786.-

this solution, it is important that no drops be allowed to collect on the blossoms, as an unsightly spot would result. The solution.

fore the spraying can be completed. More'- over, since the spray is poisonous to humans as well as thrips, the greenhouses cannot'be entered for a considerable length of time after the spraying has been finished. To open up the greenhouse, and air it out would, of course, only allow another'crop of thrips to enter, and such course is impractical for that reason.

We have discovered that the greenhouse temperature can be controlled without damage to the plants by discharging relatively small amounts of water into the air in the form of a very fine fog or mist containing sensible heat only. When this is done throughout the entire greenhouse, the temperature can be materially lowered very quickly. l\%oreover, the mist entirely envelopes the p ants and deposits a thin film of moisture over the entire exposed surface of each plant, without forming any large drops. The plants are thus enabled to absorb moisture very rapidly, without danger of disfiguring any of the foliage or blossoms.

The water fog or mist containing sensible heat only can be discharged into the air immediately after the plants have been sprayed with solution so that the temperature is not only lowered but the air is quickly cleared of the poisonous vapors and within a very few minutes the greenhouses may be safely entered. i

It is, therefore, one of the principal objects of this invention to provide'a method of protecting plants in greenhouses and the like, from the destructive attacks of pests, which shall be highly efficient and require less time, labor and expense than methods heretofore known.

Another object is to provide a method of spraying plants in greenhouses and the like with substances toxic to undesirable organisms and quickly dissipating the noxious vapors whereby the greenhouses may be safely entered within a very short period after spraying. g

It is also an object to provide a method of controlling the temperature in greenhouses and the like by means of water sprays which shall be highly efficient and which shall result in no injury to the plants or blossoms.

A further object is to provide a methodrotating nozzles adapted to discharge liquid in the form of a fog or mist.

A still further object is to provide a sprayer which shall be adapted to be rotated by the passage of liquid therethrough at low velocity and under high pressure, and which shall be adapted to free itself should it stick or jam.

Other objects and advantages will become apparent as the description proceeds in connection with the accompanying drawing in which Fig. 1 is a perspective View of an apparatus embodying our invention as installed in a greenhouse.-

Fig. 2 is a plan view of one of the rotatin atomizers.

ig. 3 is a side elevation of the atomizer shown in Fig. 2. Fig. 4 is a section view taken through the hub of the atomizer along the line 44 of fieferrin to Fig. 1, 1 indicates a green-' house in w ich are beds of plants 2. For spraying the plants there are installed a plurality of rotatable atomizers 3, with nozzles 4, which are supplied with liquid from the pipe 5, extending longitudinally of the greenhouse. The pipe 5 is mounted at an angle to the horizontal, so

- as toslope downwardly from its supply end, as illustrated, and is provided with a valve provided or faucet 6 at its opposite end which can be opened after the liquid supply to the pipe 5 is cut ofl whereby the pipe and atomizers are drained, and dripping from the nozzles 4 is prevented. Valve controlled outlets 7 are provided underneath each atomizer for the ready attachment of hose connections in cases where hand spraying or watering is found desirable. Altho for the purposes of description, we have illustrated the greenhouse as being provided with only one set of atomizers, it will be understood that a plurality of the pipes 5 may be installed whereby additional sets of atomizers may be operated if desired.

The pipe 5 is supplied with water or spray solution under high pressure by means of the pump 8 which draws water from the reservoir 9 throu h the water pipe 10 and delivers it throug the pipe 11; or by closing the valves 12, 13, and 14 and opening the valves 15, 16,'and 17. spray solution will be withdrawn from the reservoir 18 through the pipe 19 and delivered to the pi e 5 through the pipe 20. The strength 0 the spray solution can be varied if necessary by opening the valve 12 a sufiicient distance to dilute the spray solution the desired amount before it is drawn into the pump. The water or spray solution is ordinarily at atmospheric temperature but at all events it is not heated to an extent suflicient to injure the plants nor above the latent heat of vaporization.

As heretofore pointed out, it is desirable that the liquids be introduced into the greenhouse in the form of a mist or fog and for the accomplishment of this purpose atomizers of s ecial construction must be used, for examp e, such as disclosed in our Patent 1,876,250 issued September. 6, 1932. In known types of rotary sprays, the liquid is fed to the nozzles through bent pipes so that the passage of the liquid around the bends imparts an impulse to the arms which causes them to rotate. In order to overcome the inertia of the arts and the friction in the rotating hub t e velocity of the liquid passing the bends must be considerable, and usually amounts to from ten to twenty-five gallons per minute at a pressure of approximately 45 pounds per square inch. Under these conditions the li uid cannot be converted into a mist or og but issues from the nozzles in the form of solid jets or large drops. Any attempt to increase the pressure results in increasing the frictional. resistance of the hub to such an extent that rotation is .prevented and the spray is thus rendered useless.

Atomizers constructed in accordance with our invention are adapted to atomize as low as one-half gallon. of liquid per nozzle'per minute under. pressures as high as four. hundred and fifty pounds per square inch, and

under these conditions the passage of liquid therethrough will cause the parts to 'rotate soas to throw out a mist in all directions. Such an atomizer is illustrated in Figs. 2, 3, and 4 and comprises a hollow hub 21 from which rotrude a plurality of outwardly exten ing pipes 22 carrying the nozzles 4. The pipes may be bent as illustrated in order to aid rotation, as will be understood.

Many spray solutions contain a certain amount of sediment or leave a crystalline residuum when evaporated and for' this reason considerable difficulty may be experienced in starting the hub to rotate after a period of idleness. The heat encountered in greenhouses serves to evaporate the liquid from the interior of the hub, very rapidly leaving a deposit of sediment or crystals around the parts which causes them to stick and thus tends to prevent automatic starting when the pressure is again turned on. In order to overcome this difliculty, we have provided the hub 21 with a smooth bore for the reception of a plunger 23. The plunger has a central opening 24 to which is connected the hollow stem 25 which passes through the plug 26, and is screwed into the supply pipe 5. A ring 27 is provided with an annular groove which co-operates with a similar groove in the plug 26 to form a raceway for ball bearings 23, which serve to reduce friction and allow the hub to rotate easily when filled with liquid under high pressure. A packing ring 29 is provided to prevent leakage and the parts are held in operative position bymeans of the retaining ring 30. With this construction it will be seen that upon the admission of liquid under pressure to the chamber 31 the force exerted against the ceiling of the chamber will cause the hub 21 to rise with respect to the plunger 23, thus freeing the parts if they have become stuck and allowing the hub to be started rotating easil When the admission of liquid to cham r 31 is cut oil the hub 21 again settles down until the plug 32 rests upon the plunger 23.

It will also be noted that by reason of the above construction the paclnng ring 29 is automatically adjustable according to the pressure of the li uid. As the liquid pressure is increased, t e acking is compressed,

so as to expand slight y and makea tighter fit, while upon reduction .of the pressure whereby a looser fit is sufiicient, the pressure on the packing is proportionately reduced thus allowing it to loosen slightly and offer less resistance to rotation of the hub 21.

In order to aid starting and co-operate with the bends in the pipes 22, in rotating the atomizer, a twisted metal strip 33, carried by the plug 32 is laced within the hol-' low stem 25, whereby t e passage is divided into two spirally ascending passages. It

will be seen that the reaction set u by the passage of liquid therethrough wil tend to cause the atomizer to rotate.

It has been found that speeds of rotation of known types of rotating sprinklers which are from fifty to. sixt revolutions per minute are entirely too igh for the atomizer shown herein for the reason that at such speeds themist is not thrown far enough awa from the nozzle to effect the desired resu t. We have found that a speed of app'oximately twelve revolutions per minute is st for satisfactory operation of the atomizer and for discharging the mist to a proper distance. It will be understood that different speeds might be desirable under varying conditions at use and in such event the speed of rotation can be varied by adjusting the pitch of the spiral strip 33 or the angle of the bends in the pipes 22.

In operation, when it is desired to spray the plants with solution, the valves 6, 12,

13, and '14 are closed and valves 15, 16, and

17 are opened, whereupon the pump 8 is operated to fill .the pipe 5 with spray solution under ressure. The solution is forced upwardly t ru the spiral passages in the stems 25 into the chambers 31, thus simultaneously exerting a lifting and twisting force to the hubs 21, which are thereupon caused to rotate and a mist of the solution is ejected from each nozzle. With a suitable number of atomizers, it will be seen that the entire greenhouse is almost instantly filled with a floating mist or fog of solution. In this manner the pests may be destroyed in any size greenhouse within a period of about-one minute as compared with periods of hours required by other methods. 1

When it is desired to cut oil the spray solution, the valves'15, 16 and 17 are closed and the valve 6 is opened. In this manner the solution remaining in the atomizers and the pipe 5 may be drained off, thus preventing the nozzles from dripping and causing damage to the plants, and allowing the subsequent spraying of water without any preliminary spray of solution.

After the pipes are drained, the valve It will now be seen that by the use of our I novel method and apparatus we are enabled to spray the plants with a solution or spray containing substances toxic to undesirable organisms such as insecticides or funigicides, clear the air of noxious vapors, an lower the temperature ofthe greenhouse as well as accomplish other desirable results, with practically no labor and in a small fraction of the time heretofore required. Moreover, we have found that by the use of our invention we are enabled to save as much as one half the amount of spray solution heretofore necessary for destroying the undesirable organisms such as insectary ests. The control of plant diseases is simi arly facilitated and made more economical. This represents a very material savin of expense.

Having now descri in what manner the same may be used, what we claim as new and desire to secure by Letters Patent is i 1. The method of cooling greenhouses and the like which comprises introducing an unheated non-poisonous liquidtherein in the form of a to -like mist.

2. The met 0d of cooling greenhouses and the like which comprises creatin a fog of an unheated non-poisonous liqui throughout the greenhouse.

3. The method of Watering plants in greenhouses and the like which com rises envelopin them in unheated water mist of suflicient neness to dampen the plants while avoidin accumulation of large drops of liquid 1; ereon. 1 4. The method of treating plants in eenhouses and the like which comprises introducing a liquid insecticide into said greenhouse in the form of a floatin mist, and thereafter dissipating the mist o insecticide by introducing water therein in the form of a floating mist.

5. The method of treating plants whichcomprises enveloping them in a floating mist of insecticide, and thereafter dissipating the mist of. insecticide by enveloping them in an unheated floating water mist.

- 6. In combination, 'a greenhouse, means for discharging a liquid in theform of a f like mist therein, a source of liquid spray so ution, a source of'water and means for supplying said discharge means with said li uids either. alone or in combination.

' In combination, a greenhouse, an atomizer for dischargin liquid into the greenhouse in the form 0 a to -like mist,- a pump adapted to pump liquid to said atomizer, means for supp y ing liquid insecticide .to said pump, means for supplyin said pum and control means said suppy means. 8. In combination, a greehouse, anatomor each of izer for di'schargingliquid into the greenhouse. in the form of a floating mist, means -for. supplying liquid under pressure to said atomizer, means for 'supplying said first named meanswith. liquid insecticide, means for supplying-said first named means withwater, and means for regulating the supplyof each of said-liquids to said first named (1 our invention and into t e water .to

' 9. In combination, a greenhouse, a pipe extending therein," an atomizer commumcating with said pipe and means for sup lying liquid to said pipe under pressure su ment; 1 v 70 pipe means or supplying spray material to said s raying means, and means at the lower end 0 said pi means for allowing s ray material to drain therefrom to prevent ripping from the nozzles.

11. In combination, aeenhouse, and means for substantially filing said reenhouse with unheated mist of a fog-'1' e nature.

,12. In combination, a greenhouse, and means for alternately filling said house with an unheated fo -like mist of water and a fog-like mist of insecticide.

13. In combination, a greenhouse having plants therein, and means for enveloping substantially all of said plants in an uneenheated fog-like mist substantially simultane ously. 1

14. In combination, a greenhouse having plants therein, and means for alternately enveloping substantially all of said plants .veloping fog-like mist of insecticide around substantially all of said plants simultaneously, and means for re lacing said mist of insecticide with a fogke water mist. I

17. The method of treating plants in emhouses and thelike which com rises mtroducin a fog-like mist of liqui insecticide reenho'use, and thereafter introducing a og-like mist of non-poisonous liquid into said nhouse. until the mist of insecticide is gelled.

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18. The method of treating plants greenhouses and the like which comprises treating the plants with insecticide, and thereafter introducing a fog-like mist of non-poisonous liquid into said greenhouse until the insecticide fumes are dispelled.

-19. The method of treating plants which comprises enveloping them in a fog-like mist of insecticide and thereafterenveloping' them in a fog-likemist of non-poisonous liquid until the mistof insecticide is dispelled. 20. The method of treating plants in eenhouses and the like which comprises chargin into said greenhouse at a plurality ofedlocations an unheated liquid I in'the form ofamist whereby to substam tiall'y fillthe greenhouse therewith.

. 21. The method of treating plants in greenhouses and the like which comprises discharging into said greenhouse along a circular path around each of a plurality of fixed locations, an unheated liquid in the form of a mist whereby to substantially fill the greenhouse therewith.

22. The method of treating plants in greenhouses and the like which comprises discharging into said greenhouse, along a circular path around each of a plurality of fixed locations, a liquid insecticide in the form of a mist, whereby to substantially fill the greenhouse therewith.

23. The method of cooling greenhouses or similar plant enclosures having plants therein, which comprises substantiall filling said enclosure with a fog-like must of cooling liquid.

24:. The method of lowering the temperature in greenhouses and other plant en-' closures, which comprises substantially filla i ing said enclosure with a fog-like mist of a liquid containing sensible heat only.

95 25. The method of cooling greenhouses or similar plant enclosures havmg plants therein, which comprises substantially filling said enclosure with a fog-like mist of cooling liquid of sufiicient fineness to lower the temperature while avoiding the accumulation of large drops of liquid on the plants. 26. In a method of treating plants in greenhouses and similar -plant enclosures, the steps of introducing a finely divided foglike mist of solution toxic to undesirable or- V ganisms into said reenhouse, and thereafter dissipating said og-like mist by substantially filling said greenhouse with an aqueous non-toxic fog-like mist. 7 4. 27. The method of treating plants in greenhouses and the like which comprises simultaneously introducing into said greenhouses, at a pluralityof fiked locations, a 7 liquid in the form of a fog-like misfi where- Iw by all pgrtiOns of said greenhouse are substantially filled therewith.

28. In a method of treating and controlling the growth of plants in greenhouses and similar plant enclosures, the step of substantially filling said enclosure containing plants under treatment with a fog-like mist of a solution toxic to undesirable organisms.

Signed at San Jose, Galii, this 19 day June 1930. HARRY C. LASSEN.

HENRY DAHL. 

